1. Field of the Invention
The present invention relates to a differential driver with a calibration circuit and a related calibration method, and more particularly to a calibration circuit directly calibrating the deviated output resistive elements of the differential driver and a related calibration method.
2. Description of the Prior Art
Passive elements, such as resistors and capacitors, are critical elements in an integrated circuit. In a differential driving stage, there are two loading resistors utilized for matching the impedance looking to the transmission line which is coupled to the output port of the differential driving stage. Ideally, the resistance values of the loading resistors should be equal to each other. The resistances, however, may differ from the ideal value after fabrication due to process variations. If the resistance values of the loading resistors deviate from the predetermined value, the impedance matching condition between the loading resistors and the transmission line may fail, and consequently a reflected signal may be induced when the differential driving stage outputs a differential output signal to the transmission line via the output port. More specifically, the reflected signal may deteriorate the quality, such as linearity, of the differential output signal. Therefore, a mechanism is required to acquire and calibrate the deviation of passive elements in the integrated circuit.